The Southwest Oncology Group is a major multidisease, multidisciplinary cooperative therapeutic research organization with 29 Member Institutions, 22 Community Clinical Oncology Programs (CCOPs) and 148 Cooperative Group Outreach Program (CGOP) Centers throughout the country. The scientific thrust of the Group is through multidisciplinary disease oriented committees which develop important, testable hypotheses in the management of each tumor category. The Group is a powerful tool in the design and conduct of innovative therapeutic research. The long-term objective is improved treatment and potential cure of many currently incurable malignancies. This Competative Renewal Application differs from past applications in that the Southwest Oncology Group has developed a series of new initiatives designed to enhance urological cancer research, and melanoma research as well as to extend the scientific thrust of the Group from the basic science standpoint in leukemia, lymphoma and flow cytometry of many tumor categories.